What precautions do you take to keep your bike from being stolen?

[Crankin]

I truly don't worry about it. I've left my bike locked in my car uncovered, many times, at work (both in good and bad neighborhoods). If we are traveling and our bikes are on the rack, we have a very heavy duty lock system that locks them to the rack. If I am out somewhere and I have to go inside to get food, I will ask someone I'm with to watch my bike.
When I commute, I leave my bike unlocked in an entry/stairwell that only employees of my clinic use. The entrance is connected to the hospital the building is part of, but says employees only.
DH used to have a system similar to Helene's in his old SUV, but we never covered the bikes when we used it.
Maybe I'm naive, but I just don't worry about this. There is bike theft here (in the suburbs, not talking about the city). I've gone in for lunch in a couple of places with racks, without a lock at all, but these were places sort of out in the middle of nowhere. I have left my bike locked to the public rack in Concord center many times. I used to worry, but since that is not productive, I don't anymore.

[azfiddle]

We keep our bikes inside in storage /laundry room. When I ride to work, I keep my bike in my classroom. When we travel, we put on a couple of locks- cable and u-locks- on the bikes on the rack.

If I'm driving with the bike on the rack, and making a quick stop at the store, maybe I'm too casual, but I usually just use a cable lock wound around the bike and the rack. Sometimes I put it into the back of our car (Honda Fit) with tinted windows, and lock the car, but don't usually cover the bike. If I'm riding my bike and stopping at the store, I wheel it around inside unless someone in the store asks me to leave at the front where they'll watch it. If I'm riding my Surly specifically to go grocery shopping, I'll bring a u-lock.

Biggest worry- riding alone and stopping to refill a water bottle at a convenience store where it's just not easy to bring it inside. Sometimes I just won't stop if it's a more questionable neighborhood. But I try to avoid those anyway if I'm on my own. Some places I feel okay just running in to get water.